Boron nitride has been used extensively for vaporization vessels (also known as vaporization boats) used for metal evaporation. In addition to the use of solid boron nitride articles, such as vaporization vessels, boron nitride powders have found use in many applications such as coatings for high temperature molds to facilitate release of glass, metals, ceramics or the like. Boron nitride coatings can also be used as antisputter coatings for welding applications; anticorrosive coatings for various substrates; and thermally conductive/ electrically insulating coatings for electronic equipment.
In addition to boron nitride powders, many other powders such as borides, carbides and oxides of metals have utilization for various applications when applied to a substrate as a film-forming coating. To be a good film coating that can be sprayed on substrates, the powders have to be dispersed in a liquid vehicle along with a binder type ingredient to insure that the dispersed powder will adhere to the substrate. Many different types of vehicle binder solutions have been used with particulate powders to provide a sprayable composition that can be used in an aerosol can with a conventional propellant gas such as isobutane.
It is an object of the present invention to provide a powder-containing composition, such as a boron nitride-containing composition, that when applied to a surface of a substrate will produce a coating having good adherence to the substrate.
It is another object of the present invention to provide a powder-containing composition consisting essentially of particulate powder and clay dispersed in water.
It is another object of the present invention to provide a powder-containing composition that uses a minor amount of clay as a binder.
It is another object of the present invention to provide a boron nitride-containing composition comprising particulate boron nitride in combination with particulate clay dispersed in water.
It is another object of the present invention to provide a boron nitride-containing composition comprising particulate boron nitride and particulate clay in combination with aluminum nitride, titanium diboride and/or titanium dioxide dispersed in water.
It is another object of the present invention to provide an economical vehicle-binder for particulate powders that can be used to facilitate the depositing of the powders on a substrate as an adhered film or coating.
Additional objects of the invention will become evident from the description that follows.